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Allen’s Stain for Mast Cells


Allen's Stain

for Mast Cells



Tissue Sample

Paraffin sections of neutral buffered formalin fixed tissue are suitable. Mercuric chloride fixatives are reputed to emphasise metachromasia. Other fixatives may be satisfactory.


  1. Bring sections to water via xylene and ethanol.
  2. Rinse with water.
  3. Stain nuclei lightly with alum hematoxylin.
  4. Rinse with tap water and blue hematoxylin.
  5. Rinse well with water.
  6. Place in neutral red for 10 minutes.
  7. Rinse with distilled water.
  8. Differentiate with 70% ethanol up to 10 minutes.
  9. Dehydrate with 96% ethanol up to 5 minutes.
  10. Dehydrate with N-butanol up to 10 minutes.
  11. Clear with xylene and mount using a resinous medium.

Expected Results

  • Nuclei – blue
  • Mast cell granules = red

Safety Note

Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.


  1. Culling, C F A, (1976).
    Lynch’s Medical Laboratory Technology., Ed. 3. Vol. II. pp. 980
    W. B. Saunders Company, Toronto, Canada.
  2. Putt, F A, (1972).
    Manual of Histopathological Staining Methods., pp. 233
    John Wiley & Sons, London, UK.